TagAlaska Air(111)

A Des Moines resident's formal comment on the Seattle-Area Metroplex Environmental Impact Statement argues that Sea-Tac Airport's official planning assumption — that average aircraft size will grow by only 0.5% per year — is mathematically incompatible with the airport's own goal of 56 million annual passengers by 2032. The comment shows that reaching that passenger target under the current assumption would require roughly 880,000 flights per year, far exceeding the airport's infrastructure ceiling of about 517,000 operations. The author contends that airlines like Alaska and Delta are already ordering larger aircraft and expanding international routes at Sea-Tac, meaning faster fleet upgauging is not a worst-case scenario but a necessity for the plan to make sense.

A Des Moines resident's formal comment on the Sea-Tac Airport Master Plan (SAMP) Environmental Impact Statement argues that the SAMP's aircraft seat capacity assumptions are now outdated, pointing to major 2026 fleet expansions by Alaska Airlines and Delta that include significantly more and larger widebody aircraft operating from SEA. The comment contends that because larger planes carry more passengers per flight, fewer total aircraft operations would be needed to reach the SAMP's 56 million passenger target, meaning the airport could handle projected growth with less noise impact than the SAMP currently estimates. The author presents revised seat-capacity scenarios suggesting the SAMP's low-growth assumption is internally inconsistent and that updated fleet data should be incorporated into the EIS before final conclusions are drawn.